The Forestry Forum is sponsored in part by:

iDRY Vacuum Kilns


Forestry Forum
Sponsored by:


TimberKing Sawmills



Toll Free 1-800-582-0470

LogRite Tools



Norwood Industries Inc.




Your source for Portable Sawmills, Edgers, Resaws, Sharpeners, Setters, Bandsaw Blades and Sawmill Parts

EZ Boardwalk Sawmills. More Saw For Less Money!

STIHLDealers.com sponsored by Northeast STIHL


Woodland Sawmills

Peterson Swingmills

 KASCO SharpTech WoodMaxx Blades

Turbosawmill

Sawmill Exchange

Michigan Firewood, your BRUTE FORCE Authorized Dealer

FARMA


Baker Products

ECHO-Bearcat

iDRY Wood Lumber Vacuum Drying for everyon

Nyle Kiln Dry Systems






Author Topic: single belt or double belt?  (Read 1352 times)

0 Members and 1 Guest are viewing this topic.

Offline Kurban

  • member
  • *
  • Posts: 15
  • Location: St Louis, MO
  • Gender: Male
  • I'm new!
    • Share Post
single belt or double belt?
« on: March 18, 2014, 08:15:40 PM »
I am planning to assemble my sawmill soon. I have not seen a discussion of the belt requirements. I am planning to use a 10 HP 3-phase electric motor as the main power source and 21" trailer tires for the band wheels.

Question: Is a single belt adequate or should I go for double belt pulley? The issue is re;evant because if I weld the pulley to the rim, it is easier to to so with a single belt pulley. Not to mention the centrifugal clutch pulley issue.

Sal.

Offline ladylake

  • Senior Member x2
  • *****
  • Posts: 5106
  • Age: 67
  • Location: grey eagle mn
  • Gender: Male
  • I need to edit my profile!
    • Share Post
Re: single belt or double belt?
« Reply #1 on: March 18, 2014, 08:31:43 PM »
 I'd go with a double, you might get by with a single if the smallest pulley was around 7 or 8 ".    Steve
Timberking B20 14000 hours +  Case75xt grapple + forks+8" snow bucket + dirt bucket   770 Oliver   Lots(too many) of chainsaws, Like the Echo saws and the Stihl and Husky     W5  Case loader   1  trailers  Wright sharpener     Suffolk  setter Volvo MCT125c skid loader

Offline blackfoot griz

  • Senior Member
  • ****
  • Posts: 560
  • Age: 57
  • Location: Whitefish, MT
  • Gender: Male
    • Share Post
Re: single belt or double belt?
« Reply #2 on: March 18, 2014, 08:37:35 PM »
What size belt are you thinking about using? Can't you use a shaft with a keyway?

While you don't want to be smoking belts all the time, going with too much belt can be really costly. Not long ago, I had a customer that bought  a Dodge 15:1 gear reduction box from me.  It lasted 2 weeks instead of many years.  When looking in to it, the unit(running 8-10 hours daily) was going through a belt every 3 months or so. Unknown to the boss, one of the employees doubled the belt.  The end result is that the double belt far exceeded the capacity of the gearbox.  Instead of trashing a $15 belt, they trashed a $2500 gear box.

You have any pictures of your setup?

Offline bandmiller2

  • Senior Member x2
  • *****
  • Posts: 8726
  • Location: Franklin Ma.
  • Gender: Male
    • Share Post
Re: single belt or double belt?
« Reply #3 on: March 18, 2014, 08:39:04 PM »
Sal, a centrifugal clutch won't work on a motor as it always runs at its rated speed, an engine will idle and allow the clutch to release. I have a 15hp three phase motor and two "B" series belts and have never detected any slippage. I have a belt idler flat pulley to tighten and release the belts so I can start the motor unloaded. Your tires have a lot of weight to start turning so I would recommend two belts and an idler setup so the motor can start unloaded or you may be tripping breakers on startup. Frank C.
A man armed with common sense is packing a big piece

Offline morgoon

  • Full Member x2
  • ***
  • Posts: 137
  • Location: North Western Ontario...Probably further North than the other Northern Ontario
    • Share Post
Re: single belt or double belt?
« Reply #4 on: March 18, 2014, 08:48:15 PM »
While not electric

I have been using a single belt for a long time with a 14 hp Wisconsin and a snowblower style idler. Two belts would give you peace of mind though I think.

I'll try to get pics tomorrow
Homemade bandsaw, made by my mentor and dear friend Unto...who turned 85 this year

And I just made my first longbow...awesome

Offline chopperdr47

  • Full Member x2
  • ***
  • Posts: 127
  • Age: 58
  • Location: Close to Birmingham, AL... but not too close
  • Gender: Male
  • Frick 0, 190hp Propane Minneapolis Moline
    • Share Post
Re: single belt or double belt?
« Reply #5 on: March 18, 2014, 08:57:31 PM »
This might be a little involved for what you are wanting but it helped me figure what I needed to transfer 60 hp.

http://www.flexco.com/filebase/es/src/Installation_Instructions/v_belt_selecguide.pdf
If ya ain't got what ya need, use what ya got

Offline Larry

  • Senior Member x2
  • *****
  • Posts: 5958
  • Age: 71
  • Location: NW Arkansas
  • Gender: Male
    • Share Post
Re: single belt or double belt?
« Reply #6 on: March 18, 2014, 09:26:49 PM »
As Steve implied it is the small pulley that limits horsepower transfer.  Grainger has a handy dandy chart to pick belts.  You can't get there with a A belt.  With a B belt the smallest pulley for 10 HP is 6.6.  If you add a X to the belt size that means cogs and higher horsepower transmission.  With a BX you can use a 5.8 pulley.  Can't use a cog belt with a manual clutch as they are too grabby.

I've found the chart conservative for most applications.  The problem with a sawmill is you can stick the band in a wide cut and squall the belt.  That's because your 10 HP motor can put out maybe 15 - 20 HP before the circuit breaker trips.  Once you squeak the belt that puts a slick spot on it and it will slip next time even easier.

So, I might bite the bullet and go with a banded (two BX belts tied together) BX belt for peace of mind and long term economy.
Larry, making useful and beautiful things out of the most environmental friendly material on the planet.

We need to insure our customers understand the importance of our craft.

Offline YellowHammer

  • Senior Member x2
  • *****
  • Posts: 4532
  • Age: 54
  • Location: New Market, Alabama
  • Gender: Male
  • Take Steps to Save Steps
    • Share Post
    • Hobby Hardwood Alabama
Re: single belt or double belt?
« Reply #7 on: March 18, 2014, 10:25:03 PM »
Not being a belt expert, I would look to conventional electric power tools for guidance.  Every one of my electric shop tools over 5hp has at least a double belt, or a wide serpentine style single.  An LT40 has a joined triple main drive belt.  Not saying a single belt wouldn't work, but it seems like a double belt would be preferable.  It's very important that the main drive belt doesn't slip, it can cause a lot of weird problems when sawing. 
YH
HobbyHardwoodAlabama.com

Offline morgoon

  • Full Member x2
  • ***
  • Posts: 137
  • Location: North Western Ontario...Probably further North than the other Northern Ontario
    • Share Post
Re: single belt or double belt?
« Reply #8 on: March 19, 2014, 12:18:38 AM »
Well I can post up a couple pics of my mill drive in the morning that is a copy to a sister mill that runs 10hp 3ph on a single belt..

It runs thru a homemade phase converter if that makes a difference in final hp.

My mill is a temp spare tire design as well, however I have been considering an engine swap for more hp.... But this discussion has me wondering about pulley size and adding a second belt to reduce slippage.

Perhaps that is a new thread... I only mention it to say I'm not 100% happy with my cut speed but it does cut well.
Homemade bandsaw, made by my mentor and dear friend Unto...who turned 85 this year

And I just made my first longbow...awesome

Offline pineywoods

  • Senior Member x2
  • *****
  • Posts: 5156
  • Age: 83
  • Location: Marion, Louisiana
  • Gender: Male
  • Engineering analysis-just sittin thinkin about it
    • Share Post
Re: single belt or double belt?
« Reply #9 on: March 19, 2014, 12:44:06 PM »
If you run wide enough tire for a bandwheel, just run the drive belt around the tire instead of buying big expensive v belt pulleys. Sounds crazy, but I saw a pto driven genset that used a car tire and wheel for the large pulley, with the v belts running on the tire tread.  Worked good, especially if you use a double belt.
1995 Wood Mizer LT 40, Liquid cooled kawasaki,homebuilt hydraulics. Homebuilt solar dry kiln.  Woodmaster 718 planner, Kubota M4700 with homemade forks and winch, stihl  028, 029, Ms390
100k bd ft club.Charter member of The Grumpy old Men

Offline Dave Shepard

  • Senior Member x2
  • *****
  • Posts: 11130
  • Age: 2015
  • Location: Alford Massachusetts
  • Gender: Male
  • Geometrically proportional
    • Share Post
    • My homepage
Re: single belt or double belt?
« Reply #10 on: March 19, 2014, 12:50:58 PM »
I was told at the industrial shop that a B series belt will transmit 7.5 electric HP. Do you have an industrial supply house around where you are getting your belts and sheaves? They should be able to lead you in the right direction. Why do you want a centrifugal clutch on an electric motor?
Wood-Mizer LT40HDD51-WR Wireless, Kubota L48, Honda Rincon 650, TJ208 G-S, and a 60"Logrite!

Offline Magicman

  • Senior Member x2
  • *****
  • Posts: 39036
  • Age: 76
  • Location: Brookhaven, MS
  • Gender: Male
  • A "Traveling Man"
    • Share Post
    • Knothole Sawmill
Re: single belt or double belt?
« Reply #11 on: March 19, 2014, 05:41:47 PM »
  Why do you want a centrifugal clutch on an electric motor? 
I agree.  Reply #3 was very informative.
Knothole Sawmill, LLC     '98 Wood-Mizer LT40SuperHydraulic   WM Million BF Club Member   WM Pro Sawyer Network

Never allow your "need" to make money to exceed your "desire" to provide quality service.....The Magicman

Offline morgoon

  • Full Member x2
  • ***
  • Posts: 137
  • Location: North Western Ontario...Probably further North than the other Northern Ontario
    • Share Post
Re: single belt or double belt?
« Reply #12 on: March 19, 2014, 10:38:59 PM »
http://www.forestryforum.com/gallery/displayimage.php?pid=154139

I have to learn how to post pics...I just ran out of time tonight

If you look in my gallery at the only pic you will see my idler set up.

As mentioned my mill is a copy of one that runs a 10hp 3ph motor and the drive is similar

The electric mill is buried under snow and about an hour away so I won't have a pic for while :(

I have a pulley the same size as the temp spare rim behind the rim, that is bolted on in 6 spots to drive the sawhead as a single assembly.
Homemade bandsaw, made by my mentor and dear friend Unto...who turned 85 this year

And I just made my first longbow...awesome


Share via delicious Share via digg Share via facebook Share via linkedin Share via pinterest Share via reddit Share via stumble Share via tumblr Share via twitter

 


Powered by EzPortal